Your best and easiest route is going to be reading
this thread - find the post that has your model Mac listed in it and you'll find what cable(s) you need.
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Without using the cables I've already identified in the thread above:
As far as I am aware, there has not been a TV manufactured that will allow you to use an RCA audio input simultaneously with a HDMI video input.
Based on the diagrams of the back of your TV, I doubt there is any audio input that will work in conjunction with one of your HDMI inputs.
The audio input that typically works with HDMI is the stereo mini-plug that is pictured next to the VGA input. Almost all TVs that have this capability, there would be a HDMI port labeled as HDMI/DVI on the TV (I've never seen a TV that permitted this function on more than a single HDMI port).
The way your RCA ports are set up on your TV, my guess, they will only work with a component video connection.
The only thing I see on your TV connections that make me believe it may be possible is that your stereo mini-plug is labeled as DVI/VGA. Because you have no DVI input, that makes me think you might be able to use that port with one of the HDMI.
To find out, you will need to break out the owner's manual or find a copy of it for your model online and look for a section on connecting a computer via DVI. That section would show you which HDMI port you have to use and where in the menus you would go for that HDMI port to work with a separate audio port.
The other option will be to look through the TV menu for your HDMI and audio options and see if you can find a setting that permits you to change the audio for one of the HDMI ports. This option can be well hidden in the menus, sometimes almost impossible to find without the owner's manual.
